One area of design I find consistently overlooked is the small IT closet. In the last month, I’ve seen a few 5,000 sq ft pre-built offices or spec spaces where the landlord provides a very small IT closet. But look up in the IT closet ceiling and there may be no sign of mechanical cooling equipment or even an exhaust fan.
The reason I regularly hear from landlords for this oversight is that because it’s a small room, there’s not that much equipment or heat to be generated. Therefore, there’s no need for conditioning.
Hear this, just because the closet is small doesn’t mean it doesn’t generate heat that could potentially be harmful to your equipment.
Now if you’re a tenant thinking of moving in, you’re probably visualizing your current IT closet that’s overheating and tried the following remedies:
1. Leaving the door open
2. Brought in portable cooling
3. Exhausting the hot air into the plenum
4. Louver the door
5. A number of other methods to keep your equipment from shutting down.
So what do you do in the new space?
When you’re dealing with spec space, your options are limited because the mechanical design has already been completed. You’re left with figuring out how to drop in a Mr. Slim Unit and where to place the condenser; or adding an exhaust fan which is marginally helpful; dumping building air into the closet – but what happens when it shuts off at 6pm?
According to Morais Miranda, RCDD, president of New York based Technology Solutions Design Group, he advises if your power consumption is at least 5kVa, the minimum needs for an IT closet is a 1.5 ton unit minimum. That’s not a lot of gear in the rack to generate that kind of output.
Here’s the basic formula to calculate your needs:
Watts = Amps x Volts
1 Amp @120 Volts = 120 Watts
1 Watt of Power = 3.412 BTU
3.412 BTU x Watts = X BTU
1 ton of cooling is 12,000 BTU/hour, not counting people load
So to calculate a 5kVA = 1.5 Ton AC unit:
5000 x 3.412 = 17060 BTUs/12,000 BTU = 1.42 Ton
If you can’t do A/C in the new space, then you should at minimum louver the door, dump building air plus add an exhaust on a thermostat.